Overview
Where are we in the universe? When are we? How is it that human beings confined to the Earth are able to know anything about a Universe that we have no direct access to? We have only recently begun sending out probes around our Solar System, but realistically it looks like that may be the extent of what we can explore directly. How is it, then, that science can teach us anything about any of the rest of it?
If you’ve ever been curious about these things, then you’ve come to the right place. The astronomy of planets is our first step towards discovering the Universe. In fact, without the other planets in our Solar System there can be little doubt that humans would never have understood gravity, and would still believe the Earth lies fixed at the centre of the Universe.
This course is about the discovery of our Solar System and the subsequent exploration of it. We will look in detail at how the process of doing science developed as humans sought an explanation for the apparent motions of the planets with respect to background stars. We will then look in more detail at how modern astronomers are able to use observations from the confines of the Earth to learn all about objects we can only view through a telescope. We’ll see that much of our confidence in what we’ve learned comes from experimental science we have conducted on Earth, as we are able to apply the knowledge we obtain here to our astronomical observations. From there, we will embark on a systematic study of all that we now know about the objects in our Solar System—our best source of information that we can use to decode the workings of everything else we see.
This module will provide you with an introduction to our observational arena—the night sky—and an understanding of what it means to make our observations from here and now. You will be introduced to many of the conventions astronomers use when describing the night sky, and you’ll develop an understanding of how the daily and annual motions we observe as we look up translate to the motions of the Earth. In short, you’ll learn how to view the sky as an astronomer does.
Learning Objectives
When you have finished this module, you should be able to do the following:
- Develop a sense of here and now in relation to astronomical observables
- Identify why humans study astronomy, incorporating the scientific method in principle and in practice
- Explore the celestial sphere, the naming of stars and constellations, and the magnitude scale
- Explain the daily and annual cycles, and the cause of seasons on Earth
Key Terms and Concepts
- scientific method
- celestial sphere
- constellations
- magnitude scale
- equinox (vernal, autumnal)
- ecliptic
- solstice (summer, winter)
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